Suggestion:

There is a lot of map coordination going on here. People tend to use NE, NW, SE, SW alot. For me, I have to stop and think for a second to get my barring straight. That delay can be costly if you ask me. Why not just use UL, UR, LL, LR. Upper left, Upper Right, Lower Left, Lower Right. Its straight forward, no thinking involved, go lower left map, point your arrow, and run...easy no?

Initial Buffs Needed - The Rest Come When You Determine Boss Mobs
Sonic
Blur
Magic Circle Against Evil
Shield of Faith Mass
Mass Aid

Crowd Control Spells:
Dancing Ball - On Pull Points
Symbol of Stunning - On Pull Points
Solid Fog - On Pull Points
Acid Fog - On Pull Points

Pull points will be LAGGY, have Break Enchantment up just in case you need to reduce the lag.

General Buffs:
Bard Songs
Prayer
Haste
Rage
Acid Resist
Sonic Resist (Orthon)
Fire Resist (Fire Elemental)
Poison Resist
Freedom Of Movement (Earth Elemental)
Blur
Greater Heroism
Magic Circle Against Evil
Shield of Faith Mass
Mass Aid
Mass Deathward (Kobold)
Mass Spell Resistance (Gnoll)

Weapons To Use:
Vorpal - Mob Beater
For Boss Mobs, Its Situational - Greater Gnoll, Orc, Elemental Banes.  Holy of Pure Good, Transmuting Of Pure Good, True Chaos (Devil), Mineral II GreenSteel etc...

Tips:
The tree's in the corners you start out in, will regenerate your spell points slowly. Only one person can use at a time. The first person in a tree gets the SP/HP tic. Moving in and out of the tree makes it work faster, but is not necessary. Jumping in the back of the tree also makes it work faster.

The Boss Mobs: (You only get 1 from each position)
Devil - Orthon - Lion (Spawn In Pos. 1)
Fire Elemental - Earth Elemental (Spawn in Pos. 2)
Gnoll - Troll (Spawn in Pos. 3)
Kobold - Trog - Orc(Spawn in Pos. 4)

Basic Layout/Strat:

Pull all trash mobs to the SW Corner.  Take them all down there.  Once down, 1 person goes to check out the mobs.  Depending on the pull, will determine who goes where.  Typically, Lion, Devil, Orthon go to NE.  Fire is typically stuck in the cubby on the west side, just north of the SW corner.  Earth is typically pulled to the SE Corner.  All other mobs are pulled to the SW.  You usually want a caster and some evasion builds on the elementals.  Evasion builds should get the primary aggro, and once down 1/4, caster kicks in with them, to bring it down 3/4 total.  Caster then gets to the center, and lays down some firewalls on the crystal waiting for all mobs to drop.  1 Healer should go to the NE with the crew handling Pos. 1 mobs.  The rest stick SW.  If people need healing in the cubby or on earth, 1 of the healers should be a floater and help them out.

Note:
There is only one way around, and its like a U. You cannot go directly from Upper Left, to Upper Right. You'll have to run from UL, to LL, to LR, to UR in order to get there.

Everybody should be getting buffed up at this point, in the south west.  After all buffs are in place, those casting them should go get their spell points back at a free tree.  After you have all of your buffs, move to your designated corner.

Single pull the first mobs from the EAST side.  You will either get Pos. 1 or Pos. 2 to come down.  Let an evasion build get the Elemental if it comes first, the puller should take Pos. 1 mob up to the NE and stay there with it.  Someone from SW should go get the rest once the primary two are in place.

All of the mobs must die nearly at the same time.

You must prep your mobs, kind of like the pillars in the dragon, or the fire/ice in tempest spine. Get them to a little under 1/4 health, and wait, once all designated mini group leaders shout out they are ready, the ONE will call for an overall kill.  SW Mobs always get killed first.  If Fire is up or Lion, or both are up, they go last.